﻿/*!
* accounting.js v0.3.2
* Copyright 2011, Joss Crowcroft
*
* Freely distributable under the MIT license.
* Portions of accounting.js are inspired or borrowed from underscore.js
*
* Full details and documentation:
* http://josscrowcroft.github.com/accounting.js/
*/

(function (root, undefined) {

    /* --- Setup --- */

    // Create the local library object, to be exported or referenced globally later
    var lib = {};

    // Current version
    lib.version = '0.3.2';


    /* --- Exposed settings --- */

    // The library's settings configuration object. Contains default parameters for
    // currency and number formatting
    lib.settings = {
        currency: {
            symbol: "$", 	// default currency symbol is '$'
            format: "%s%v", // controls output: %s = symbol, %v = value (can be object, see docs)
            decimal: ".", 	// decimal point separator
            thousand: ",", 	// thousands separator
            precision: 2, 	// decimal places
            grouping: 3		// digit grouping (not implemented yet)
        },
        number: {
            precision: 0, 	// default precision on numbers is 0
            grouping: 3, 	// digit grouping (not implemented yet)
            thousand: ",",
            decimal: "."
        }
    };


    /* --- Internal Helper Methods --- */

    // Store reference to possibly-available ECMAScript 5 methods for later
    var nativeMap = Array.prototype.map,
		nativeIsArray = Array.isArray,
		toString = Object.prototype.toString;

    /**
    * Tests whether supplied parameter is a string
    * from underscore.js
    */
    function isString(obj) {
        return !!(obj === '' || (obj && obj.charCodeAt && obj.substr));
    }

    /**
    * Tests whether supplied parameter is a string
    * from underscore.js, delegates to ECMA5's native Array.isArray
    */
    function isArray(obj) {
        return nativeIsArray ? nativeIsArray(obj) : toString.call(obj) === '[object Array]';
    }

    /**
    * Tests whether supplied parameter is a true object
    */
    function isObject(obj) {
        return obj && toString.call(obj) === '[object Object]';
    }

    /**
    * Extends an object with a defaults object, similar to underscore's _.defaults
    *
    * Used for abstracting parameter handling from API methods
    */
    function defaults(object, defs) {
        var key;
        object = object || {};
        defs = defs || {};
        // Iterate over object non-prototype properties:
        for (key in defs) {
            if (defs.hasOwnProperty(key)) {
                // Replace values with defaults only if undefined (allow empty/zero values):
                if (object[key] == null) object[key] = defs[key];
            }
        }
        return object;
    }

    /**
    * Implementation of `Array.map()` for iteration loops
    *
    * Returns a new Array as a result of calling `iterator` on each array value.
    * Defers to native Array.map if available
    */
    function map(obj, iterator, context) {
        var results = [], i, j;

        if (!obj) return results;

        // Use native .map method if it exists:
        if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);

        // Fallback for native .map:
        for (i = 0, j = obj.length; i < j; i++) {
            results[i] = iterator.call(context, obj[i], i, obj);
        }
        return results;
    }

    /**
    * Check and normalise the value of precision (must be positive integer)
    */
    function checkPrecision(val, base) {
        val = Math.round(Math.abs(val));
        return isNaN(val) ? base : val;
    }


    /**
    * Parses a format string or object and returns format obj for use in rendering
    *
    * `format` is either a string with the default (positive) format, or object
    * containing `pos` (required), `neg` and `zero` values (or a function returning
    * either a string or object)
    *
    * Either string or format.pos must contain "%v" (value) to be valid
    */
    function checkCurrencyFormat(format) {
        var defaults = lib.settings.currency.format;

        // Allow function as format parameter (should return string or object):
        if (typeof format === "function") format = format();

        // Format can be a string, in which case `value` ("%v") must be present:
        if (isString(format) && format.match("%v")) {

            // Create and return positive, negative and zero formats:
            return {
                pos: format,
                neg: format.replace("-", "").replace("%v", "-%v"),
                zero: format
            };

            // If no format, or object is missing valid positive value, use defaults:
        } else if (!format || !format.pos || !format.pos.match("%v")) {

            // If defaults is a string, casts it to an object for faster checking next time:
            return (!isString(defaults)) ? defaults : lib.settings.currency.format = {
                pos: defaults,
                neg: defaults.replace("%v", "-%v"),
                zero: defaults
            };

        }
        // Otherwise, assume format was fine:
        return format;
    }


    /* --- API Methods --- */

    /**
    * Takes a string/array of strings, removes all formatting/cruft and returns the raw float value
    * alias: accounting.`parse(string)`
    *
    * Decimal must be included in the regular expression to match floats (defaults to
    * accounting.settings.number.decimal), so if the number uses a non-standard decimal 
    * separator, provide it as the second argument.
    *
    * Also matches bracketed negatives (eg. "$ (1.99)" => -1.99)
    *
    * Doesn't throw any errors (`NaN`s become 0) but this may change in future
    */
    var unformat = lib.unformat = lib.parse = function (value, decimal) {
        // Recursively unformat arrays:
        if (isArray(value)) {
            return map(value, function (val) {
                return unformat(val, decimal);
            });
        }

        // Fails silently (need decent errors):
        value = value || 0;

        // Return the value as-is if it's already a number:
        if (typeof value === "number") return value;

        // Default decimal point comes from settings, but could be set to eg. "," in opts:
        decimal = decimal || lib.settings.number.decimal;

        // Build regex to strip out everything except digits, decimal point and minus sign:
        var regex = new RegExp("[^0-9-" + decimal + "]", ["g"]),
			unformatted = parseFloat(
				("" + value)
				.replace(/\((.*)\)/, "-$1") // replace bracketed values with negatives
				.replace(regex, '')         // strip out any cruft
				.replace(decimal, '.')      // make sure decimal point is standard
			);

        // This will fail silently which may cause trouble, let's wait and see:
        return !isNaN(unformatted) ? unformatted : 0;
    };


    /**
    * Implementation of toFixed() that treats floats more like decimals
    *
    * Fixes binary rounding issues (eg. (0.615).toFixed(2) === "0.61") that present
    * problems for accounting- and finance-related software.
    */
    var toFixed = lib.toFixed = function (value, precision) {
        precision = checkPrecision(precision, lib.settings.number.precision);
        var power = Math.pow(10, precision);

        // Multiply up by precision, round accurately, then divide and use native toFixed():
        return (Math.round(lib.unformat(value) * power) / power).toFixed(precision);
    };


    /**
    * Format a number, with comma-separated thousands and custom precision/decimal places
    *
    * Localise by overriding the precision and thousand / decimal separators
    * 2nd parameter `precision` can be an object matching `settings.number`
    */
    var formatNumber = lib.formatNumber = function (number, precision, thousand, decimal) {
        // Resursively format arrays:
        if (isArray(number)) {
            return map(number, function (val) {
                return formatNumber(val, precision, thousand, decimal);
            });
        }

        // Clean up number:
        number = unformat(number);

        // Build options object from second param (if object) or all params, extending defaults:
        var opts = defaults(
				(isObject(precision) ? precision : {
				    precision: precision,
				    thousand: thousand,
				    decimal: decimal
				}),
				lib.settings.number
			),

        // Clean up precision
			usePrecision = checkPrecision(opts.precision),

        // Do some calc:
			negative = number < 0 ? "-" : "",
			base = parseInt(toFixed(Math.abs(number || 0), usePrecision), 10) + "",
			mod = base.length > 3 ? base.length % 3 : 0;

        // Format the number:
        return negative + (mod ? base.substr(0, mod) + opts.thousand : "") + base.substr(mod).replace(/(\d{3})(?=\d)/g, "$1" + opts.thousand) + (usePrecision ? opts.decimal + toFixed(Math.abs(number), usePrecision).split('.')[1] : "");
    };


    /**
    * Format a number into currency
    *
    * Usage: accounting.formatMoney(number, symbol, precision, thousandsSep, decimalSep, format)
    * defaults: (0, "$", 2, ",", ".", "%s%v")
    *
    * Localise by overriding the symbol, precision, thousand / decimal separators and format
    * Second param can be an object matching `settings.currency` which is the easiest way.
    *
    * To do: tidy up the parameters
    */
    var formatMoney = lib.formatMoney = function (number, symbol, precision, thousand, decimal, format) {
        // Resursively format arrays:
        if (isArray(number)) {
            return map(number, function (val) {
                return formatMoney(val, symbol, precision, thousand, decimal, format);
            });
        }

        // Clean up number:
        number = unformat(number);

        // Build options object from second param (if object) or all params, extending defaults:
        var opts = defaults(
				(isObject(symbol) ? symbol : {
				    symbol: symbol,
				    precision: precision,
				    thousand: thousand,
				    decimal: decimal,
				    format: format
				}),
				lib.settings.currency
			),

        // Check format (returns object with pos, neg and zero):
			formats = checkCurrencyFormat(opts.format),

        // Choose which format to use for this value:
			useFormat = number > 0 ? formats.pos : number < 0 ? formats.neg : formats.zero;

        // Return with currency symbol added:
        return useFormat.replace('%s', opts.symbol).replace('%v', formatNumber(Math.abs(number), checkPrecision(opts.precision), opts.thousand, opts.decimal));
    };


    /**
    * Format a list of numbers into an accounting column, padding with whitespace
    * to line up currency symbols, thousand separators and decimals places
    *
    * List should be an array of numbers
    * Second parameter can be an object containing keys that match the params
    *
    * Returns array of accouting-formatted number strings of same length
    *
    * NB: `white-space:pre` CSS rule is required on the list container to prevent
    * browsers from collapsing the whitespace in the output strings.
    */
    lib.formatColumn = function (list, symbol, precision, thousand, decimal, format) {
        if (!list) return [];

        // Build options object from second param (if object) or all params, extending defaults:
        var opts = defaults(
				(isObject(symbol) ? symbol : {
				    symbol: symbol,
				    precision: precision,
				    thousand: thousand,
				    decimal: decimal,
				    format: format
				}),
				lib.settings.currency
			),

        // Check format (returns object with pos, neg and zero), only need pos for now:
			formats = checkCurrencyFormat(opts.format),

        // Whether to pad at start of string or after currency symbol:
			padAfterSymbol = formats.pos.indexOf("%s") < formats.pos.indexOf("%v") ? true : false,

        // Store value for the length of the longest string in the column:
			maxLength = 0,

        // Format the list according to options, store the length of the longest string:
			formatted = map(list, function (val, i) {
			    if (isArray(val)) {
			        // Recursively format columns if list is a multi-dimensional array:
			        return lib.formatColumn(val, opts);
			    } else {
			        // Clean up the value
			        val = unformat(val);

			        // Choose which format to use for this value (pos, neg or zero):
			        var useFormat = val > 0 ? formats.pos : val < 0 ? formats.neg : formats.zero,

			        // Format this value, push into formatted list and save the length:
						fVal = useFormat.replace('%s', opts.symbol).replace('%v', formatNumber(Math.abs(val), checkPrecision(opts.precision), opts.thousand, opts.decimal));

			        if (fVal.length > maxLength) maxLength = fVal.length;
			        return fVal;
			    }
			});

        // Pad each number in the list and send back the column of numbers:
        return map(formatted, function (val, i) {
            // Only if this is a string (not a nested array, which would have already been padded):
            if (isString(val) && val.length < maxLength) {
                // Depending on symbol position, pad after symbol or at index 0:
                return padAfterSymbol ? val.replace(opts.symbol, opts.symbol + (new Array(maxLength - val.length + 1).join(" "))) : (new Array(maxLength - val.length + 1).join(" ")) + val;
            }
            return val;
        });
    };


    /* --- Module Definition --- */

    // Export accounting for CommonJS. If being loaded as an AMD module, define it as such.
    // Otherwise, just add `accounting` to the global object
    if (typeof exports !== 'undefined') {
        if (typeof module !== 'undefined' && module.exports) {
            exports = module.exports = lib;
        }
        exports.accounting = lib;
    } else if (typeof define === 'function' && define.amd) {
        // Return the library as an AMD module:
        define([], function () {
            return lib;
        });
    } else {
        // Use accounting.noConflict to restore `accounting` back to its original value.
        // Returns a reference to the library's `accounting` object;
        // e.g. `var numbers = accounting.noConflict();`
        lib.noConflict = (function (oldAccounting) {
            return function () {
                // Reset the value of the root's `accounting` variable:
                root.accounting = oldAccounting;
                // Delete the noConflict method:
                lib.noConflict = undefined;
                // Return reference to the library to re-assign it:
                return lib;
            };
        })(root.accounting);

        // Declare `fx` on the root (global/window) object:
        root['accounting'] = lib;
    }

    // Root will be `window` in browser or `global` on the server:
} (this));